Improvement in schqll-sawtng machines



UNITED STATES PATENT Ormea.'

` WILLIAM H. DOBSON, OF MEDINA, NEVVVYORK, ASSIGNOR TO HIMSELF AND HOMER BELDING, OF SAME PLACE.

IMPROVEMENT 1N SGROLL=SAWING MACHINES.

Specification forming part of Letters Patent No. 92,288, dated July 6, 1869.

To all whom it may concern i v Be it known that I, WILLIAM H. DOBSON, of Medina, in the county of Orleans and State of New York, have invented a new and Improved Scroll-Sewing Machine 5 and I do hereby declare that the following is a full, clear, and exact description thereof, which will enable others skilled in the art to make and use the same, reference being had to the accompanying drawings, forming part of this specifica-l tion, in which- Figure 1 is a front view of my improved ma chine, part of the table being broken away to show the construction, Fig. 2 is a detail sectional view of the same taken through the line :v fr, Fig. 1. Fig. 3 is a detail sectional rF'iew of the same taken through the line y y,

ig. 1. v

Similar letters of .reference indicate like parts.

My invention has for its object to furnish an improved tension-strain scroll-sawing machine, simple in construction, and convenient,

effective, and reliable in use; 'and it consists in the construction and combination of various parts of the machine, as hereinafter more fully described.

A are the supports or frame of the machine, to the upper part of which is attached the table B, which may be circular or of any other convenient form.

C is an upright or bar, which is supported in a vertical position above the table B by arms 0r supports D, attached to the side edges of the.bar C and to the frame A, as shown in Fig. 1, and which are made of such a form as not to interfere with feeding the timber to the saw.4

E is a guide attached to the lower part of the bar or upright C, to keep` the saw in proper position while moving up and down.

F is a horizontal bar placed at right angles to the upright C, and adjustably secured in place by the thumb-screw Gr, which passes through a vertical slot in the upper part of said upright C, and screws into the middle part of the said cross-bar F, so that the said bar may be conveniently raised and lowered to adjust its position to the length of the saw to be used.

H are short'rollers or shafts which pass through the bar F, near its ends, and which are adjustably secured in place by the setscrews I, or by ratchets and pawls, as may be desired or convenient.

To the shafts or rollers H are attached the ends of the springs J, in such positions that they may act from or against each other, as shown in Fig. 1.

To the free ends of the springs J are at tached the ends of the connecting cord or wire K, to the middle part of which is attached the upper end ofthe cord or rod L, the lower end of which is attached to the upper end of the saw M.

The lower end of the saw M is securely .attached to the cross-head or sliding plate N,

which'slides up and down in the ways 0, and the edges of which are bent over to tit into the semicircular grooves in said ways, as shown in Fig. 3.

By this construction, should the sliding plate or cross-head N become heated and eX- pand, it will expand in the arc of a circle, so that it cannot bind or become too tight.

I? is a connecting-rod or pitman, the upper end of which is pivoted to the sliding crosshead or plate N, and the lower end ot' which is pivoted to the crank-'pin of the crankwheel Q.

rIhe crank-wheel Q, is attached to the shaft R, which revolves in bearings in the lower part of the frame A, and to which is attached the drive-pulley S. l

T are saw-guides which are placed in an inclined position in the lower part ofthe table B in such positions that their upper corners may be flush with the upper surface of the said `table B, as shown in Fig. 1.

The guides are adjustably held in place by the angular bar U, which is slotted for the passage of the saw M, and which is adjustably secured in place by the set-screw V, as shown in Fig. 2.

By this construction, as the upper ends of the saw-guides T wear oft', they may be conveniently. moved up close to the saw M,

so -as to prevent the work from being slivered upon its under side by said saw.

Having thus described my invention, I

claim as new and desire to secure by Letters structed substantially as herein shown and Patentdescribed, in combination with the Ways O l. The adjustable bar F, adjustable rollers and saw M, as and for the purpose set forth. H, springs J, and cord K, supporting the up# WILLIAM H. DOBSON. per end of the saw, constructed and arranged Witnesses: as described, for the purpose specified. S. H. CLARK,

2. The sliding crosshead or plate N, con- WILLARD E. WALDRON. 

